Researchers from the Queen Elizabeth University Hospital, Glasgow have reported that Computed Tomography (CT) Imaging is not accurate enough to diagnose pleural mesothelioma or other pleural malignancies.
Their tests on 315 patients have revealed that CT scan showed varying results in either ruling out or confirming the mesothelioma in more than half of the cases.
In their research report, "The diagnostic performance of routinely acquired and reported computed tomography imaging in patients presenting with suspected pleural malignancy", published in the journal "Lung Cancer" on 13th November, 2016, the Scottish researchers have highlighted the fact that accuracy rate of CT scan, performed for diagnosis of pleural malignancies, was only 58%.
CT Scan Imaging and the Diagnosis of Mesothelioma
When a person with the occupational history of high asbestos exposure and symptoms like relentless coughing, wheezing, chest pain and sudden weight loss, come to see a physician; while including malignant mesothelioma in his differential diagnosis, the physician go through various tests like CT scans and X- Rays to accurately diagnose the problem.
CT scan is the radiological method used for the diagnosis of mesothelioma or other pleural malignancies, in which cross- sectional images are created with special X-rays, which are compiled to form a three-dimensional model.
CT scanning is thought to be one of the most advanced and highly accurate diagnostic tools, but according to this recent research, approximately half of the benign CT scan results (showing the absence of any malignancy of -54% of total patients) were later diagnosed with a pleural malignancy. Indicating that this method is not as specific and sensitive as it was originally accepted.
To access the reliability of CT scanning, this study was performed on 315 patients, which were diagnosed with mesothelioma or other pleural malignancies between January 2014 and April 2016.
CT Scan Results
"Probable Malignant effusion", "suspicion of malignancy", and "disseminated malignancy" are considered to be the malignant reports from CT scan imaging. While reports like "No cause identified", "intermediate", or "no evident malignancy" are considered to be the benign results.
CT scan correctly diagnosed pleural mesothelioma in 58% of the patients, and negatively predicted 54% of the cases. While the scans interoperated by thoracic radiologists resulted in the correct diagnosis of mesothelioma.
The study has emphasized on the presence of specialized thoracic radiologist because the accuracy of results in specialized radiology reporting was 68%, while in no specialized thoracic reporting the accuracy was 53%.
Combination of Diagnostic Methods
According to the report, other diagnostic procedures including pleural biopsy must also be incorporated with CT, thus to get more accurate and quick diagnosis. Because delayed diagnosis significantly poses a bad impact on the survival rate of mesothelioma patients.
In other studies, positron emission tomography (PET) combined with CT scan have also been described as an improved diagnostic method for accurate diagnosis of mesothelioma. In PET, radioactive tracers marked with special dye, are used to highlight the area with the higher metabolic rate. This can also provide an indication of cancer.
The researchers concluded that relying solely on the CT scan results is not sufficient enough to confirm or negate the presence of pleural malignancy or mesothelioma. For the accurate diagnosis of pleural mesothelioma and other pleural malignancies, a combination of CT scan with Positron Emission Tomography (PET) is very important.